A study conducted in the Hutterite community found that immunizing children with the live attenuated influenza vaccine, the kind found in the flu nasal spray, did not provide better direct or community protection against influenza than the inactivated influenza vaccine, or standard flu shot. The protection, however, was similar in both groups. The findings are published in Annals of Internal Medicine.

Influenza, or flu, is a major cause of morbidity and mortality. Vaccinating children against flu can both protect them individually and also protect the community from becoming infected, which is known as herd immunity. Earlier studies conducted in young children suggested that the nasal spray vaccine provided better direct protection against flu than the standard shot, which would suggest better heard immunity as well. However, most comparative flu vaccine studies assess direct protection only.

Researchers conducted a cluster randomized trial in a Hutterite colony where people live communally and are relatively isolated from cities and towns to determine whether vaccinating children and adolescents with the flu nasal spray provided better direct and community protection than the standard flu shot. The authors randomly assigned 1,186 children in 52 Hutterite colonies in Alberta and Saskatchewan, Canada to receive the nasal spray vaccine and 3,425 children to receive the standard flu shot. They found that the nasal spray vaccine was very similar to the standard flu shot in providing direct protection to children and also in creating herd immunity.

According to the study lead author, Mark Loeb, MD of McMaster University, while these findings did not show superiority of the live vaccine, rather that both vaccines had a similar effect, they differ from recent observational studies showing that the nasal spray vaccine was ineffective, which had prompted the Centers for Disease Control Advisory Committee on Immunization Practices (ACIP) to recommend that the nasal spray not be used during the 2016-2017 flu season.

Researchers found a lack of strong evidence to compare the benefits and harms of revascularization using percutaneous transluminal renal angioplasty with stent placement (PTRAS) versus medical therapy alone for atherosclerotic renal artery stenosis (ARAS). The report is published in Annals of Internal Medicine.

ARAS is a narrowing of arteries that carry blood to one or both of the kidneys. It is more prevalent in older people and can lead to hypertension and kidney damage. Treatment options for ARAS include medical therapy - aggressive blood pressure control, statins, and antiplatelets - or renal artery revascularization with continued medical therapy. PTRAS is the current standard for revascularization. A 2007 systematic review of management strategies for ARAS concluded that evidence did not support one treatment approach over another. Since then, two large trials have been conducted. Given the inconclusive prior review and the availability of new evidence, investigators sought to reevaluate the comparative benefits and harms of strategies for management of patients with ARAS and to identify factors that may predict which patients are most likely to benefit from each intervention.

The researchers reviewed 83 published studies to compare the benefits and harms of PTRAS versus medical therapy alone for ARAS. Overall, the evidence did not support a benefit with PTRAS over medical therapy alone in most patients with ARAS. Observational studies did suggest that some high risk patients may have improved outcomes with PTRA and anecdotal evidence suggest that some patients with acute decompensation due to ARAS benefit clinically from revascularization. A reanalysis of available research or more targeted studies may be needed to determine the comparative effectiveness of the two interventions.

Note: For an embargoed PDF, please contact Cara Graeff. The lead author, Dr. Ethan Balk, can be reached through David Orenstein at david_orenstein@brown.edu or 401-863-1862.

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